The biggest aspect of Fantasy Football is the draft - where you select your players before the start of the season. So the area where you could apply some actual hacking is the projection/simulation of player performance to come up with your own rankings. Hopefully, this could allow you to pick undervalued players - so similar to predicting stocks. Basically you can treat it as a statistical modeling exercise and go from there.

There is no realtime aspect to fantasy sports, you are usually setting a roster weekly, waiting for the games to be played for the week, and then seeing the results. So something like high frequency trading doesn't really apply.

There's a brilliant technical paper written on this subject: http://eprints.soton.ac.uk/340382/

The authors' (completely algorithmically managed) team managed to get a rank of ~25000 when competing against 2.5Million human players. Pretty damn good if you ask me. This paper is about Fantasy Soccer though. However the same rules apply to Fantasy Football too.